#include <x/qp.H> std::string s; typedef std::back_insert_iterator<std::string> ins_iter_t; std::string input_string; ins_iter_t iter=std::copy(input_string.begin(), input_string.end(), x::qp_encoder<ins_iter_t>(ins_iter_t(s))).eof();
The
x::qp_encoder
template class defines an output iterator that encodes its output
sequence using quoted-printable encoding, as described in section 6.7 of
RFC 4648, and writes the encoded output sequence to another output
iterator, the “underlying” output iterator.
The template parameter is the underlying iterator class, and the
constructor takes an underlying iterator class instance.
After iterating over the sequence, eof() must
get called to flush any remaining unencoded sequence
x::qp_encoder does not often buffer anything,
and generally encodes everything on the fly; but there are some edge
conditions where a character gets buffered internally.
eof() returns the new value of the underlying
output iterator.
x::qp_encoder's constructor
has three optional parameters:
The line width. By default, x::qp_encoder
inserts a soft line break every 76 characters. Set the line width
to 0, in order to disable soft line breaks.
A bool flag, that defaults to
false. Set the flag to true to
use CRLF sequence for a newline, instead of a
LF. This takes effect for both the output
sequence that x::qp_encoder receives, and
the output sequence iterated by the underlying output iterator.
The flag gets effectively ignored when soft line breaks get disabled
by setting the line width to 0. This results in all
CR and LF characters getting
encoded, together with all other control characters.
An instance of a traits class, that optionally specifies which characters should be encoded in addition to the control characters and the non-ASCII characters:
class extra_encoded { public: static bool encode(char c) { return c == '\'' || c == 34; } }; typedef std::back_insert_iterator<std::string> ins_iter_t; typedef x::qp_encoder<ins_iter_t, extra_encoded> encoder_t;
x::qp_encoder's second optional template
parameter is a class with an encode() function,
which returns true for any characters, in addition
to control characters and non-ASCII characters that are always encoded.
This is used in environments where additional characters must be encoded
for syntax-related reasons. This example results in apostrophes and
quote characters also getting encoded.
encode() can be a function or a class member.
An instance of the traits class gets passed as the last optional
parameter to x::qp_encoder's constructor,
defaulting to the default constructor for the traits class.
std::string encoded; std::string orig; typedef std::back_insert_iterator<std::string> ins_iter_t; typedef x::qp_decoder<ins_iter_t> decoder_t; ins_iter_t iter=std::copy(encoded.begin(), encoded.end(), decoder_t(ins_iter_t(orig))).eof();
The
x::qp_decoder
template class defines an output iterator that performs the opposite
quoted-printable decoding,
and writes the decoded output sequence to the
underlying output iterator.
The template parameter is the underlying iterator class, and the
constructor takes an underlying iterator class instance.
After iterating over the sequence, eof() returns
the new value of the underlying output iterator.
x::qp_decoder does not buffer anything, so
eof() has no real effect other than
returning the new value of the underlying output iterator.